Noticed this for a few builds now.
You'll get a raid of 6 scythers (as I just did), kill them then when you come to disassemble them there are not six corpses. I'm playing on sea ice so I had to install my machining table specifically to process them so I know they didn't get processed when I wasn't looking. My 6 scythers had somehow become 3 available to process.
Have noticed this a few times in this playthrough which has spanned various B19 and 1.0 builds. Sorry no other info but it is definitely happening.
Are you going a long time between killing them and processing them, and are they being stored outside in the meantime? Maybe they're degrading. How many hit points are on the ones that are still there?
No, it was immediately after killing them. I'm watching closely each time now to see if I can see it again.
Are you running any mods?
Can you post an output_log after this has occurred? It'd be very helpful.